| Q: |
What are the various analytical techniques available in the chemical lab? |
| A: |
The analytical techniques are broadly classified in two groups as Chromatography and Spectroscopy. In the former we have HPLC, GC, HPTLC etc. and in the latter we have UV-Vis, IR, ICAP etc. |
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| Q: |
What is HPLC? |
| A: |
HPLC is an acronym, which stands for High Performance Liquid Chromatography. Here in a silica-based column (stationary phase) is used to separate the analytes by using a liquid (mobile phase), which is made to run through by means of a peristaltic pump. Finally after entering and traversing the length of the column the analytes are detected by means of a detector. |
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| Q: |
What is HPTLC and how is it different from HPLC? |
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HPTLC stands for High Performance Thin Layer Chromatography. It is different from HPTLC as it does not involve the use of column and pump. Herein there is a silica-coated plate analogous to the HPLC column where the analytes are separated and the mobile phase is a developing solvent, which moves along the length of the plate through capillary action. |
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| Q: |
What is GC and how does it differ from HPLC? |
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GC stands for Gas Chromatography wherein the mobile phase is a gas such as hydrogen, helium, argon etc. and the stationary phase is a silica capillary column of very long length. In contrast to this HPLC has a liquid mobile phase and a shorter column. |
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| Q: |
Which all toxic compounds are present in leather and textile items after usual tanning processes that need to be identified and quantified? |
| A: |
There are various compounds which are toxic and carcinogenic namely Azo dyes, Formaldehyde, Chrome VI, Pentachlorophenol, Tetrachlorophenol, heavy metals (Pb, Cd, etc). |
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| Q: |
What is Azo test in leather and textile items? |
| A: |
During the process of tanning various dyes and pigments are employed. These azo compounds are reduced to convert them into amines. A list of twenty amines has been identified as carcinogenic. These are detected and quantified by means of capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). |
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| Q: |
How is formaldehyde content estimated? |
| A: |
Formaldehyde is found to be hazardous when present in quantities above the prescribed limits. HPLC with diode array detection is used for detection of formaldehyde content. |
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| Q: |
What is the test for Chrome VI? |
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The metal chromium in the hexavalent state is a hazardous and banned chemical that is detected using UV-Visible spectrophotometer. |
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| Q: |
How are chlorinated phenols estimated? |
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Chlorinated phenols such as pentachlorophenol are often used as biocide in leather and poses serious health hazard. This is detected using GC coupled with electron capture detector. This detector is sensitive and specific to detect halogenated compounds. |
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| Q: |
What are the other important chemical tests conducted? |
| A: |
Some other important tests conducted on leather and textile items are as follows:
- pH
pH is a crucial quality control parameter of leather. Highly acidic leather can cause severe skin diseases. pH here in the chemical lab is determined using a digital pH meter.
- Detection of heavy metals
Cadmium, Arsenic, Lead, Tin, Antimony, Nickel, Cobalt and Copper are detected at the level of ppb (parts per billion) using ICP (Inductively Coupled Argon Plasma Emission Spectrometer).
- Chrome content of leather
The chrome content (Cr2O3) of leather is determined by the fusion method and gives an idea about the extent of chrome tanning in leather.
- Detection of nickel in metal trims
Nickel-plating on metallic components is known to cause serious skin allergy problems. Hence nickel is banned in all metallic trims that come in direct contact with the skin.
- Moisture and Oil/Fat content of leather
The softness and pliability of leather depends a lot on moisture content. Similarly oil and fat should be present in the right proportion in leather. Very low fat could make the leather dry and brittle and high fat content could pose adhesion problems. These are therefore routine quality control tests.
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| Q: |
What are the prices/sample and the time for each test? |
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Please refer to the price list section. |
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